clean up fixed bitfields

Author: yuzawa-san

iabgpp-encoder/src/main/java/com/iab/gpp/encoder/bitstring/BitString.java

@@ -1,6 +1,9 @@
 package com.iab.gpp.encoder.bitstring;
 
 import java.util.BitSet;
+import java.util.PrimitiveIterator.OfInt;
+import java.util.stream.IntStream;
+import com.iab.gpp.encoder.datatype.encoder.BaseIntegerSet;
 import com.iab.gpp.encoder.datatype.encoder.IntegerBitSet;
 import com.iab.gpp.encoder.datatype.encoder.IntegerSet;
 import com.iab.gpp.encoder.error.DecodingException;
@@ -46,7 +49,7 @@ public static final BitString of(String str) {
   }
 
   public IntegerSet toIntegerSet() {
-    return new IntegerBitSet(bitSet, from, to);
+    return new IntegerBitSet(bitSet, from, to, 1);
   }
 
   @Override

iabgpp-encoder/src/main/java/com/iab/gpp/encoder/datatype/EncodableFixedBitfield.java

@@ -16,7 +16,7 @@ public final class EncodableFixedBitfield extends AbstractEncodableBitStringData
   public EncodableFixedBitfield(int numElements) {
     super(true);
     this.numElements = numElements;
-    this.value = IntegerBitSet.withLimit(numElements);
+    this.value = new IntegerBitSet(numElements);
   }
 
   public void encode(BitStringBuilder builder) {

iabgpp-encoder/src/main/java/com/iab/gpp/encoder/datatype/encoder/IntegerBitSet.java

@@ -17,23 +17,21 @@ public final class IntegerBitSet extends BaseIntegerSet {
   protected final BitSet bitSet;
   protected final int from;
   protected final int to;
+  private final int adjustment;
 
-  public IntegerBitSet(BitSet bitSet, int from, int to) {
+  public IntegerBitSet(BitSet bitSet, int from, int to, int adjustment) {
     this.bitSet = bitSet;
     this.from = from;
     this.to = to;
+    this.adjustment = adjustment;
   }
 
-  public static final IntegerBitSet withLimit(int limit) {
-    return new IntegerBitSet(new BitSet(0), 0, limit);
-  }
-
-  public IntegerBitSet(int size) {
-    this(new BitSet(size), 0, MAX_COLLECTION_SIZE);
+  public  IntegerBitSet(int limit) {
+    this(new BitSet(0), 0, limit, 0);
   }
 
   public IntegerBitSet() {
-    this(0);
+    this(MAX_COLLECTION_SIZE);
   }
 
   @Override
@@ -47,6 +45,14 @@ public int size() {
     return count;
   }
 
+  private int getOffset(int value) {
+    int offset  = from - adjustment + value;
+    if (offset < from) {
+      throw new IndexOutOfBoundsException();
+    }
+    return offset;
+  }
+
   @Override
   public void clear() {
     bitSet.clear(from, to);
@@ -59,7 +65,7 @@ public boolean isEmpty() {
 
   @Override
   public boolean containsInt(int value) {
-    int offset = from + value;
+    int offset = getOffset(value);
     return offset < to && bitSet.get(offset);
   }
 
@@ -85,7 +91,7 @@ public int nextInt() {
         }
         int next = cursor;
         cursor = bitSet.nextSetBit(cursor + 1);
-        return next - from;
+        return next - from + adjustment;
       }
     };
   }
@@ -110,8 +116,8 @@ public void addRange(int start, int end) {
     if (end < start) {
       throw new IllegalArgumentException("Negative length range");
     }
-    int realStart = from + start;
-    int realEnd = from + end;
+    int realStart = getOffset(start);
+    int realEnd = getOffset(end);
     if (realStart >= to) {
       logOutOfRange(start);
       return;
@@ -124,7 +130,7 @@ public void addRange(int start, int end) {
   }
 
   public boolean addInt(int value) {
-    int offset = from + value;
+    int offset = getOffset(value);
     if (offset >= to) {
       logOutOfRange(value);
       return false;
@@ -138,7 +144,7 @@ public boolean addInt(int value) {
   }
 
   public boolean removeInt(int value) {
-    int offset = from + value;
+    int offset = getOffset(value);
     if (offset >= to) {
       logOutOfRange(value);
       return false;

iabgpp-encoder/src/main/java/com/iab/gpp/encoder/datatype/encoder/OptimizedFibonacciRangeEncoder.java

@@ -38,7 +38,7 @@ public static IntegerSet decode(BitString bitString) throws DecodingException {
     } else {
       BitString bits = bitString.substring(17);
       int length = bits.length();
-      IntegerBitSet value = new IntegerBitSet(length + 1);
+      IntegerBitSet value = new IntegerBitSet();
       for (int i = 0; i < length; i++) {
         if (bits.getValue(i)) {
           value.addInt(i + 1);

iabgpp-encoder/src/main/java/com/iab/gpp/encoder/datatype/encoder/OptimizedFixedRangeEncoder.java

@@ -37,7 +37,7 @@ public static IntegerSet decode(BitString bitString) throws DecodingException {
     } else {
       BitString bits = bitString.substring(17);
       int length = bits.length();
-      IntegerBitSet value = new IntegerBitSet(length + 1);
+      IntegerBitSet value = new IntegerBitSet();
       for (int i = 0; i < length; i++) {
         if (bits.getValue(i)) {
           value.addInt(i + 1);

iabgpp-encoder/src/test/java/com/iab/gpp/encoder/datatype/encoder/FixedBitfieldEncoderTest.java

@@ -73,7 +73,7 @@ public void testEncode7() {
 
   @Test
   public void testEncode8() {
-    IntegerSet set = IntegerBitSet.withLimit(5);
+    IntegerSet set = new IntegerBitSet(5);
     for(int i = 0; i <= 10; i++) {
       set.addInt(i);
     }
@@ -82,7 +82,7 @@ public void testEncode8() {
 
   @Test
   public void testEncode9() {
-    IntegerBitSet set = IntegerBitSet.withLimit(5);
+    IntegerBitSet set = new IntegerBitSet(5);
     set.addRange(0,10);
     Assertions.assertEquals(Set.of(0,1,2,3,4), set);
   }